A beam energy measurement probe and detector thereof

Abstract

The present invention discloses a beam energy probe and a detector thereof, belonging to the technical field of accelerator beam diagnosis, wherein the probe comprises a shielding support body and a signal sensing and extraction device, the signal sensing and extraction device comprises a sensing electrode and a feedthrough, the feedthrough exposes a signal extraction feedthrough connector; when the particle beam passes through the inside of the sensing electrode, the sensing electrode generates a sensing signal; the sensing signal is finally transmitted to the feedthrough, and finally the sensing signal is extracted by the signal extraction feedthrough connector. The present invention discloses a beam energy measurement probe with high sensitivity; the present invention discloses a beam energy detector, which sends the sensing signal on the signal extraction feedthrough connector to an oscilloscope, and a computer compares and analyzes different sensing signals, and calculates the energy of the beam through the time difference of the sensing signal and the detector installation distance.

Description

Technical Field

[0001] The invention belongs to the technical field of particle accelerator beam diagnosis, and in particular relates to a beam energy measurement probe and a detector thereof. Background Art

[0002] Heavy ions are less destructive to healthy human tissues, and therefore have the advantages of being able to kill tumor cells accurately and efficiently during treatment, and have now become a hot topic in tumor radiotherapy and chemotherapy research. The medical heavy ion accelerator (English name: Heavy Ion Medical Machine, shortened to HIMM) is my country's first heavy ion tumor treatment device with independent intellectual property rights, including a cyclotron, a synchronization ring, and a beam vacuum pipe connected between the two for beam transmission, as well as a treatment terminal. Among them, the synchronization ring is also called a synchrotron, which is a device that accumulates and accelerates charged particles by circulating them along a circular orbit. Its specific structural form can be referred to in Chinese invention patent CN200580019535.2.

[0003] After the high-energy particle beam flows out of the cyclotron and before it flows into the synchronization ring through the beam vacuum pipe, the beam intensity needs to be accurately detected to provide accurate beam energy parameters. The beam of the cyclotron is then diagnosed based on the beam energy parameters. If necessary, the energy of the beam before entering the synchronization ring needs to be matched before the matched beam can be injected into the synchronization ring for cyclotron acceleration. Therefore, providing accurate beam energy parameters is an important guarantee for obtaining high-quality beams and is also the key to the success of beam acceleration.

[0004] However, existing beam signal or energy detectors have low sensitivity, are easily interfered with, have a poor signal-to-noise ratio, and are unable to accurately measure beam energy and intensity, resulting in the inability to observe the energy of the beam of a medical heavy ion accelerator in real time. Summary of the invention

[0005] The object of the present invention is to provide a beam energy probe and a detector thereof, so as to solve the problem that the existing beam signal or energy detector has low sensitivity and cannot observe the beam energy in real time.

[0006] To achieve the above object, the present invention adopts the following technical solution: a beam energy measurement probe, comprising:

[0007] A shielding support body, including a shielding cylinder;

[0008] The signal sensing and extraction device comprises a sensing electrode and a feedthrough, wherein the sensing electrode and the feedthrough are electrically connected; the sensing electrode is arranged on the inner wall of the shielding cylinder; the feedthrough is arranged in the shielding support body and exposes a signal extraction feedthrough connector for external connection;

[0009] When the particle beam passes through the annular space in the induction electrode in the shielding tube, the induction electrode generates an induced charge to form an induction signal, which is transmitted to the feed-through and finally led out by the signal lead-out feed-through connector. The shielding support body can shield the influence of environmental noise on the induction signal.

[0010] Preferably, the shielding support body also includes a shielding tube, a supporting tube and a flange; the shielding tube is connected to one end of the supporting tube through the shielding tube, and the flange is arranged on the other end of the supporting tube; the outer walls of the shielding tube, the shielding tube and the supporting tube are electrically connected in sequence.

[0011] Preferably, the tube end connecting the support tube and the shielding tube is closed to form a blind end, a feed-through is provided at the blind end of the support tube, one end of the shielding tube is provided on the blind end of the support tube through the feed-through, and the other end of the shielding tube is provided on the shielding tube, thereby realizing that the shielding tube, the shielding tube and the outer wall of the support tube are electrically connected in sequence.

[0012] Preferably, the blind end of the support tube and both sides of the shielding tube are connected by support rods respectively, and the lengths of the two support rods connecting the blind end of the support tube and the shielding tube are adjustable to achieve fine adjustment of the position of the shielding tube.

[0013] Preferably, the signal sensing and lead-out device also includes an electrode connector and a signal lead-out terminal, the sensing electrode is a circular copper ring, which is arranged on the inner wall of the shielding tube and is isolated and insulated from the shielding tube by a plurality of electrical insulating parts; the electrode connector is a copper tube body with openings at both ends, and an electrode connector through-hole is provided at the connection between the shielding tube and the shielding tube, one end of the electrode connector passes through the electrode connector through-hole, and the outer wall of the other end of the electrode connector is fixed on the sensing electrode and electrically connected to the sensing electrode; the signal lead-out terminal includes a plug pin and a feed-through butt joint, and the feed-through butt joint is electrically connected to the feed-through; the plug pin includes a guide core and a strip cluster mesh cover, the guide core is fixedly connected to the feed-through butt joint, the plug pin is inserted into the electrode connector and the middle part of the strip cluster mesh cover contacts the inner wall of the electrode connector, and the two are plugged and matched with each other.

[0014] Preferably, the bar cluster mesh cover comprises a plurality of Hastelloy bars, both ends of which are fixed to the butt joints of the feed-through, and the Hastelloy bars are clustered around the guide core to form the thick bar cluster mesh cover in the middle.

[0015] Preferably, the feed-through butt joint is a cylinder, and the guide core is fixed to the center of the bottom surface of the feed-through butt joint and is integrally formed to ensure that the guide core is still in the center position of the bar cluster mesh cover after the Hastelloy bars of the bar cluster mesh cover are squeezed; wherein, the Hastelloy bars of the bar cluster mesh cover elastically protrude in all directions when not under pressure, and the middle outer diameter of the bar cluster mesh cover is larger than the inner diameter of the inner wall of the electrode joint. When the pin is inserted into the electrode joint, the Hastelloy bars of the bar cluster mesh cover are compressed and contracted, touching the inner wall of the electrode joint inside the electrode joint and being forced to close.

[0016] Preferably, the feedthrough comprises a conductive intermediate, an electrical insulating layer and a shielding sleeve, the blind end of the support tube is provided with a feedthrough through hole, the shielding sleeve is fixed on the feedthrough through hole and the two ends of the shielding sleeve are electrically connected to the blind end of the support tube and the shielding tube respectively; the conductive intermediate passes through the interior of the shielding sleeve and exposes both ends; the electrical insulating layer is a ceramic material, and the electrical insulating layer is arranged in the annular space between the conductive intermediate and the shielding sleeve to separate the conductive intermediate from the shielding sleeve; the outer ends of the conductive intermediate and the shielding sleeve extend outward to form a signal lead-out feedthrough joint, which is used as an external interface; the inner end of the conductive intermediate is fixedly connected to the feedthrough joint of the signal lead-out terminal.

[0017] Preferably, the shielding sleeve is nested in the shielding tube, and a conductive mesh and a clamp are provided at the connection between the shielding sleeve and the shielding tube, the conductive mesh includes a plurality of Hastelloy bars, the plurality of Hastelloy bars form a circle around the outer wall of the shielding tube, and one end of each Hastelloy bar extends into the pipe mouth of the shielding tube to contact the outer wall of the shielding sleeve of the feed-through and is clamped by the pipe mouth of the shielding tube, and one end of each Hastelloy bar is distributed on the outer wall of the shielding tube and is tightened by the clamp.

[0018] The present invention discloses a beam energy detector, comprising a plurality of the above-mentioned beam energy measurement probes, which are used to be installed on a beam vacuum pipeline between a cyclotron and a synchronization ring of a medical heavy ion accelerator, wherein the beam energy detector comprises a beam vacuum pipeline butt joint pipe, wherein the beam vacuum pipeline butt joint pipe is provided with a beam vacuum pipeline inlet, a beam vacuum pipeline outlet, a molecular pump interface, an ion pump interface and a flange interface,

[0019] Wherein, the beam vacuum pipeline inlet and the beam vacuum pipeline outlet are arranged opposite to each other and are used to be installed in the beam vacuum pipeline and docked therewith;

[0020] The molecular pump interface and the ion pump interface are used to connect the molecular pump and the ion pump respectively to maintain the vacuum environment in the beam vacuum pipe butt joint tube; the beam energy measurement probe is arranged in the beam vacuum pipe butt joint tube, the flange is sealed and connected to the flange interface of the beam vacuum pipe butt joint tube, and the induction electrode is located at the center of the beam vacuum pipe; the beam energy detector also includes a preamplifier, an oscilloscope and a computer; the signal input end of the preamplifier is connected to the signal lead-out feedthrough connector of the feedthrough through a signal line; the signal output end of the preamplifier is connected to the signal input end of the oscilloscope; the signal output end of the oscilloscope is connected to the computer.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] (1) The present invention discloses a beam energy measurement probe, wherein a shielding tube, a shielding pipe, a conductive net, a shielding sleeve of a feedthrough and a support tube are connected in sequence from bottom to top to form a shielding support body, which shields the environmental electromagnetic field; an induction electrode, an electrode connector, a signal lead-out terminal and a conductive intermediate of a feedthrough are connected in sequence from bottom to top to form a circuit in the shielding support body that leads the induction signal to the signal lead-out feedthrough connector. When the particle beam passes through the induction electrode in the shielding tube of the probe, the induction electrode generates an induction charge to form an induction signal; the induction signal is finally transmitted to the feedthrough, and finally the induction signal is led out by the signal lead-out feedthrough connector. The present invention discloses a beam energy measurement probe, which has a compact structure and stable performance, ensures stable operation of the beam in beam diagnosis, has high mechanical precision and high sensitivity, meets the requirements of good shielding function and good contact of the connector under high vacuum and baking conditions, solves the problem of low sensitivity of existing beam signals or energy detectors, and can be used to match the beam energy in real time according to the monitoring results to optimize the beam quality.

[0023] (2) The present invention discloses a beam energy measurement probe, which not only shields beam radiation, but also has a shielding support body that is highly elastic and resistant to high temperatures, and maintains tight contact even when deformed at baking temperatures. Deformation and displacement after high-temperature baking will not affect the tight contact of the signal shielding, thereby satisfying the requirements of having good shielding function and good joint contact under high vacuum conditions.

[0024] (3) The present invention discloses a beam energy measurement probe, wherein the lead-out feedthrough interface of the feedthrough is arranged at the bottom of the support tube. After the signal lead-out feedthrough connector is tightened, it is not easy to be touched by mistake, which not only ensures that the signal lead-out feedthrough connector is in close contact and does not loosen under the deformation of the baking temperature, but also effectively prevents the signal feedthrough connector from being damaged by collision. The feedthrough adopts a ceramic-sealed high-vacuum feedthrough, and the signal lead-out terminal adopts an all-metal material. The feedthrough is connected to the sensing electrode through the all-metal signal lead-out terminal, without other additional signal connection cables, and has a low gas emission rate and high temperature resistance. It can not only meet the use of ultra-high vacuum and high and low temperature environments, but also effectively reduce the structural deformation and displacement in high-temperature baking and superconducting low-temperature environments, improve good anti-deformation ability, and effectively ensure good conduction of radio frequency signals.

[0025] (4) The present invention discloses a beam energy measurement probe, wherein one end of a plurality of Hastelloy bars is annularly fixed on the feedthrough joint, the middle of the plurality of Hastelloy bars surrounds the guide core, and the other ends of the plurality of Hastelloy bars are clustered in front of the guide core and gathered into a point, forming a bar cluster mesh cover with a pointed front end and a thick middle, thereby ensuring that the Hastelloy bars are centered after being squeezed. In addition, the Hastelloy bars of the bar cluster mesh cover elastically protrude in all directions when not under pressure, and the outer diameter of the middle part of the bar cluster mesh cover is larger than the inner diameter of the inner wall of the electrode joint. When the pin is inserted into the electrode joint, the Hastelloy of the bar cluster mesh cover is compressed and contracted, and touches the inner wall of the electrode joint and is forced to close. This also ensures that when the pin is inserted into the electrode joint, the middle part of the bar cluster mesh cover contacts the inner wall of the electrode joint, and the two are plugged and matched with each other.

[0026] (5) The present invention discloses a beam energy measurement detector, in which a plurality of beam energy measurement probes are installed on a beam vacuum pipe between a cyclotron and a synchronization ring of a medical heavy ion accelerator, a flange of each beam energy measurement sensing probe is sealed and connected to a flange interface of a butt pipe of the beam vacuum pipe, and a sensing electrode is located at the center of the beam vacuum pipe, and a sensing signal on a signal lead-out feedthrough connector is led out to a preamplifier, and after being amplified by the preamplifier, the signal is connected to an oscilloscope, and the shape of the beam bunch can be monitored by the oscilloscope; a computer compares and analyzes the sensing signals collected by different beam energy measurement probes, and the corresponding beam energy is given after the time difference of the sensing signals collected by the oscilloscope and the installation distance are calculated, and displayed on a display screen of the computer; in addition, the signal output by the preamplifier is connected to a phase-locked amplifier, and the signal output by the phase-locked amplifier is collected by an acquisition card and displayed on a computer, thereby realizing real-time monitoring of the beam current. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a three-dimensional view of the beam energy measurement probe provided by Embodiment 1 of the present invention in a vertically inverted state;

[0028] Figure 2 is a front view of the beam energy measurement probe provided by Embodiment 1 of the present invention in a vertically inverted state;

[0029] Figure 3 is a side view of the beam energy measurement probe provided by Embodiment 1 of the present invention in a vertically inverted state;

[0030] Figure 4 is a top view of the beam energy measurement probe provided by Embodiment 1 of the present invention in a vertically inverted state;

[0031] Figure 5 is along Figure 2 Sectional view along line AA;

[0032] Figure 6 yes Figure 5 The enlarged view of the M in the middle;

[0033] Figure 7 is along Figure 3 Sectional view along the midline BB;

[0034] Figure 8 yes Figure 7 The enlarged view of the N position in the middle;

[0035] Fig. 9 It is a schematic diagram of the structure of the sensing electrode and the electrode connector provided in Example 1 of the present invention.

[0036] Fig.10 is a schematic structural diagram of a signal lead-out terminal provided in Embodiment 1 of the present invention;

[0037] Fig.11 is a cross-sectional view of a signal lead-out terminal provided in Embodiment 1 of the present invention;

[0038] Fig.12 is a schematic structural diagram of a conductive mesh provided in Example 1 of the present invention;

[0039] Fig.13 This is a distribution diagram of the beam energy measurement probe provided in Example 2 of the present invention applied to a medical heavy ion accelerator;

[0040] Fig.14 It is a schematic diagram of the structure of a detector formed by installing a beam energy measurement probe in a horizontal state in a beam vacuum pipe provided in Embodiment 2 of the present invention;

[0041] Fig.15 This is a connection diagram of the detector signal output provided in Example 2 of the present invention.

[0042] Description of reference numerals: 1-shielding support body, 11-shielding cylinder, 110-ceramic part, 12-shielding tube, 13-support tube, 130-blind end, 14-flange, 15-support rod;

[0043] 2-signal sensing and extraction device, 21-sensing electrode, 22-electrode connector, 23-signal extraction terminal, 231-pin, 2311-conductor core, 2312-cluster mesh cover, 232-feedthrough joint; 24-feedthrough, 241-conductive intermediate, 242-electrical insulation layer, 243-shielding sleeve; 251-conductive mesh; 252-clamp;

[0044] 3-beam vacuum pipeline, 31-beam vacuum pipeline inlet, 32-beam vacuum pipeline outlet, 33-molecular pump interface, 34-ion pump interface, 35-flange interface, 36-support plate;

[0045] 4- Cyclotron;

[0046] 5- Synchronizing ring. DETAILED DESCRIPTION

[0047] First of all, it should be noted that the "vertical inverted state" in the present invention refers to the state in which the beam energy detector as a whole remains vertical when the flange is facing upward and the support tube is facing downward, and the "horizontal lateral state" refers to the state in which the beam energy detector as a whole remains horizontal and is arranged horizontally relative to the beam vacuum pipeline. The dotted arrow indicates the beam direction. The terms "upper", "lower", "front", "back", "inner", "outer", "horizontal", "vertical" and the like indicate the orientation or position relationship based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the system or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the above components. If not otherwise stated, the above terms have no special meaning and cannot be understood as indicating or implying relative importance. Unless otherwise clearly specified and limited, the terms "installation", "setting", and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] The present invention discloses a beam energy probe and a detector thereof, wherein the shielding tube, shielding tube, conductive net, shielding sleeve of feedthrough and support tube of the beam energy measurement probe are connected in sequence from bottom to top to form a shielding support body, shielding the environmental electromagnetic field; the induction electrode, electrode connector, signal lead-out terminal and conductive intermediate of the feedthrough are connected in sequence from bottom to top to form a circuit in the shielding support body to lead the induction signal to the signal lead-out feedthrough connector, when the particle beam passes through the induction electrode in the shielding tube of the probe, the induction electrode generates an induction charge to form an induction signal; the induction signal is finally transmitted to the feedthrough, and finally the induction signal is led out by the signal lead-out feedthrough connector. The beam energy measurement probe disclosed by the present invention has a compact structure and stable performance, ensuring stable operation of the beam in beam diagnosis, high mechanical precision and high sensitivity, meeting the requirements of good shielding function and good contact of the connector under high vacuum and baking conditions, solving the problem of low sensitivity of existing beam signal or energy detector, and can be used to match the beam energy according to the monitoring results in real time to optimize the beam quality.

[0049] Embodiment 1: A beam energy measurement probe

[0050] Embodiment 1 provides a beam energy measurement probe, and its structure is described in detail below with reference to the accompanying drawings.

[0051] The beam energy measurement probe 100 includes a shielding support 1 and a signal sensing and extraction device 2.

[0052] The shielding support body 1 comprises a shielding cylinder 11 and a support tube 13.

[0053] The signal sensing and extraction device 2 includes a sensing electrode 21 and a feed-through 24.

[0054] The induction electrode 21 is electrically connected to the feed-through 24, and the shielding tube 11 is electrically connected to the outer wall of the support tube 13.

[0055] The sensing electrode 21 is a circular copper ring, which is arranged on the inner wall of the shielding tube 11. The feed-through piece 24 is arranged at the bottom of the support tube 13 and exposes a signal lead-out feed-through signal connector for external connection;

[0056] When the particle beam passes through the annular space inside the induction electrode 21 in the shielding tube 11, the shielding support 1 can shield the influence of the environmental electromagnetic field on the induction signal on the signal sensing and extraction device 2. When the beam passes through the inside of the induction electrode 21, an induced charge is generated to form an induction signal, which is transmitted to the feed-through 24 and finally led out by the signal lead-out feed-through connector.

[0057] In addition, the signal sensing and extraction device 2 can also be positioned in space through the shielding support body 1 .

[0058] refer to Figures 1 to 3 The shielding support body 1 includes a shielding tube 11, a shielding tube 12, a support tube 13 and a flange 14 from bottom to top.

[0059] The shielding tube 11 is connected to one end of the support tube 13 through the shielding tube 12, and the flange 14 is arranged on the other end of the support tube 13;

[0060] The outer walls of the shielding cylinder 11 , the shielding tube 12 and the supporting tube 13 are electrically connected in sequence.

[0061] Specifically, the tube end of the support tube 13 connected to the shielding tube 12 is closed to form a blind end 130, and the two ends of the shielding tube 12 are respectively arranged on the blind end 130 of the support tube 13 and the shielding tube 11, so that the shielding tube 11, the shielding tube 12 and the outer wall of the support tube 13 are electrically connected. Specifically, the blind end 130 of the support tube 13 is provided with a feed-through 24, and the blind end 130 of the support tube 13 is connected to the shielding tube 12 through the feed-through 24.

[0062] In order to facilitate fine adjustment of the position of the shielding tube 11, the blind end 130 of the support tube 13 and the shielding tube 11 are connected on both sides by support rods 15, and the lengths of the two support rods 15 connecting the blind end of the support tube 13 and the shielding tube 11 are adjustable to achieve fine adjustment of the position of the shielding tube 11. Specifically, an earlobe is provided on both sides of the shielding tube 11, each earlobe is provided with a support rod through-hole, and the support rod 15 is a full-thread screw, and the support rod 15 passes through the support rod through-holes on the earlobe and is fixed with a nut.

[0063] In addition, the connection between the shielding tube 11 and the support tube 13 through the support rod 15 enhances the stability of the shielding tube 11. The distance between the support rod 15 and the shielding tube 11 can be adjusted through the support rod 15 to achieve fine-tuning of the position of the shielding tube 11 and ensure the accuracy of the probe position.

[0064] The annular space in the shielding tube 11 is used for the high-energy particle beam to pass through, and the flange 14 is used for docking with the flange interface 35 on the beam vacuum pipe 3 .

[0065] refer to Figures 4 to 10 The signal sensing and extraction device 2 includes a sensing electrode 21, an electrode connector 22, a signal extraction terminal 23 and a feedthrough 24.

[0066] The sensing electrode 21 is a circular copper ring with good conductivity. It is arranged on the inner wall of the shielding tube 11 and is isolated and insulated from the shielding tube 11 by a plurality of electrical insulating parts 110. Specifically, a plurality of screw holes are provided on the shielding tube 11. The electrical insulating part 110 is a ceramic part. The electrical insulating part 110 is clamped in the shielding tube 11 to fix the sensing electrode 21. The electrical insulating part 110 is fixed to the shielding tube 11 by screws to prevent the electrical insulating part 110 from moving.

[0067] The electrode connector 22 is a copper tube body with two ends opened. The connection between the shielding tube 12 and the shielding cylinder 11 is provided with an electrode connector through-hole. One end of the electrode connector 22 passes through the electrode connector through-hole. The outer wall of the other end of the electrode connector 22 is fixed on the sensing electrode 21 and is electrically connected to the sensing electrode 21, and is used to output the signal sensed by the sensing electrode 21, such as Figure 6 , Figure 8 and Fig. 9 shown.

[0068] More specifically, the sensing electrode 21 is made of an oxygen-free copper ring, and the sensing electrode 21 is connected to the electrode connector 22 via threads.

[0069] refer to Figure 6 and Figure 8 The signal lead-out terminal 23 includes a pin 231 and a feed-through butt joint 232 , and the feed-through butt joint 232 is electrically connected to the feed-through 24 .

[0070] refer to Fig.10 The pin 231 includes a core guide 2311 and a strip mesh cover 2312.

[0071] Specifically, the bar cluster mesh cover 2312 includes a plurality of Hastelloy bars, which are bent and shaped Hastelloy bars. Both ends of the Hastelloy bars are fixed to the feed-through joint 232. The plurality of Hastelloy bars are clustered around the guide core 2311 to form a thick bar cluster mesh cover 2312 in the middle. Fig.10 and Fig.11 shown.

[0072] As a specific implementation method in which a guide core 2311 is fixedly connected to a feed-through butt joint 232, preferably, the feed-through butt joint 232 is a cylinder, and the guide core 2311 is fixed to the center of the bottom surface of the feed-through butt joint 232 and is integrally formed to ensure that the Hastelloy bars of the bar cluster mesh cover 2312 are still in the center position of the bar cluster mesh cover 2312 under the action of the guide core 2311 after being extruded.

[0073] Among them, Hastelloy is a nickel-based corrosion-resistant alloy, which is mainly divided into two categories: nickel-chromium alloy and nickel-chromium-molybdenum alloy. Hastelloy has good corrosion resistance, thermal stability, electrical conductivity and high temperature resistance, and is mostly used in aviation, chemical fields, etc. The Hastelloy strips of the bar cluster mesh cover 2312 are made of high-temperature resistant Hastelloy strips. The Hastelloy still has good elasticity after high-temperature degassing at 800℃. If there is no high-temperature requirement, the Hastelloy strips can be replaced by non-high-temperature resistant beryllium bronze or beryllium zinc copper.

[0074] The insertion pin 231 is inserted into the electrode connector 22 and the middle of the strip cluster mesh cover 2312 contacts the inner wall of the electrode connector 22, and the two are plugged and matched with each other.

[0075] Specifically, the Hastelloy bars of the bar cluster mesh cover 2312 elastically bulge out in all directions when not under pressure, and the outer diameter of the middle part of the bar cluster mesh cover 2312 is larger than the inner diameter of the inner wall of the electrode connector 22. When the pin 231 is inserted into the electrode connector 22, the Hastelloy bars of the bar cluster mesh cover 2312 are compressed and contracted, touching the inner wall of the electrode connector 22 inside the electrode connector 22 and being forced to close.

[0076] As a specific embodiment of electrically connecting the feedthrough joint 232 to the feedthrough 24, refer to Figure 6 and Figure 8 The feed-through 24 includes a conductive intermediate body 241, an electrical insulating layer 242 and a shielding sleeve 243.

[0077] The blind end 130 of the support tube 13 is provided with a feed-through hole, the shielding sleeve 243 is fixed on the feed-through hole, and the two ends of the shielding sleeve 243 are electrically connected to the blind end 130 of the support tube 13 and the shielding tube 12 respectively;

[0078] The conductive intermediate body 241 passes through the interior of the shielding sleeve 243 and exposes both ends;

[0079] The electrical insulation layer 242 is made of ceramic material and is disposed in the annular space between the conductive intermediate body 241 and the shielding sleeve 243 to separate the conductive intermediate body 241 from the shielding sleeve 243;

[0080] The outer ends of the conductive intermediate body 241 and the shielding sleeve 243 extend outward to form a signal lead-out feed-through connector, which is used as an external interface; wherein the lead-out feed-through interface is arranged on the blind end 130 at the bottom of the support tube 13. After the signal lead-out feed-through connector is tightened, it is not easy to be accidentally touched, and the collision damage of the signal lead-out feed-through connector can be effectively prevented.

[0081] Preferably, the signal lead-out feed-through connector is a 50Ω impedance connector.

[0082] The inner end of the conductive intermediate body 241 is fixedly connected to the feedthrough joint 232 of the signal lead-out terminal 23; specifically, a conductive intermediate body hole is provided in the feedthrough joint 232 of the signal lead-out terminal 23, and the conductive intermediate body 241 passes through the shielding sleeve 243 and is inserted into the conductive intermediate body hole and fixed by screws.

[0083] The feed-through 24 is a prior art, which is a ceramic-sealed vacuum environment connector that meets the requirements for ultra-high vacuum use and is connected to the blind end 130 of the support tube 13 by flange argon arc welding.

[0084] In order to achieve electrical connection between the shielding sleeve 243 of the feed-through 24 and the shielding tube 12, the shielding sleeve 243 is nested in the shielding tube 12, and a conductive mesh 251 and a clamp 252 are provided at the connection between the shielding sleeve 243 and the shielding tube 12, wherein the conductive mesh 251 is an elastic conductive mesh.

[0085] refer to Fig.12 The conductive mesh 251 includes a plurality of Hastelloy alloy bars, which form a circle around the outer wall of the shielding tube 12, and one end of each Hastelloy alloy bar extends into the tube opening of the shielding tube 12 to contact the shielding sleeve of the feed-through 24. The outer wall of 243 is clamped by the tube opening of the shielding tube 12, and one end of each Hastelloy alloy bar is distributed on the outer wall of the shielding tube 12 and is clamped by the clamp 252.

[0086] refer to Figure 6 and Figure 8 , the shielding tube 11, the shielding tube 12, the conductive mesh 251, the shielding sleeve 243 of the feed-through 24 and the blind end 130 of the support tube 13 are all conductive materials from bottom to top, such as stainless steel. The shielding tube 11, the shielding tube 12, the conductive mesh 251, the shielding sleeve 243 of the feed-through 24 and the blind end 130 of the support tube 13 are sequentially connected to form a shielding support body 1;

[0087] The sensing electrode 21 , the electrode connector 22 , the signal lead-out terminal 23 and the conductive intermediate body 241 of the feed-through 24 are sequentially connected from bottom to top to form a circuit in the shielding support body 1 for leading the sensing signal to the signal lead-out feed-through connector.

[0088] When the particle beam passes through the induction electrode 21 in the shielding tube 11 of the probe 100 , the induction electrode 21 generates induced charges to form an induced charge signal;

[0089] The sensing electrode 21 transmits the sensing signal to the electrode connector 22, and the electrode connector 22 transmits the sensing signal to the pin 231 of the signal lead-out terminal 23. The sensing signal is transmitted to the conductive intermediate 241 of the feed-through 24 through the feed-through connector 232 of the signal lead-out terminal 23, and finally the sensing signal is led out by the signal lead-out feed-through connector.

[0090] Specifically, the shielding cylinder 11, the shielding tube 12, the conductive mesh 251, the shielding sleeve 243 of the feed-through 24 and the support tube 13 are made of metal materials with a low gas outflow rate. The shielding cylinder 11, the shielding tube 12, the conductive mesh 251, the shielding sleeve 243 of the feed-through 24 and the blind end 130 of the support tube 13 are welded in sequence from bottom to top to form a shielding support body 1. The shielding support body 1 has high elasticity and high temperature resistance, and is still in close contact under deformation at the baking temperature. The deformation and displacement after high-temperature baking will not affect the close contact of the signal shielding, and meets the requirements of good shielding function and good contact of the joints under high vacuum conditions.

[0091] Embodiment 2: A beam energy detector

[0092] Embodiment 2 provides a beam energy detector, including several beam energy measurement probes 100 of Embodiment 1, and its structure is described in detail below with reference to the accompanying drawings.

[0093] Two beam energy measurement probes 100 are installed on the beam vacuum pipe 3 between the cyclotron 4 and the synchronization ring 5 of the medical heavy ion accelerator. Fig.13 shown.

[0094] The beam energy detector consists of a beam vacuum pipe butt joint,

[0095] refer to Fig.14 The beam vacuum pipeline butt joint is provided with a beam vacuum pipeline inlet 31, a beam vacuum pipeline outlet 32, a molecular pump interface 33, an ion pump interface 34 and a flange interface 35.

[0096] The beam vacuum pipeline inlet 31 and the beam vacuum pipeline outlet 32 ​​are arranged opposite to each other, and are used to be installed in the beam vacuum pipeline 3 and docked therewith;

[0097] The molecular pump interface 33 and the ion pump interface 34 are used to connect the molecular pump and the ion pump respectively, so as to maintain the vacuum environment in the beam vacuum pipeline connecting tube;

[0098] The beam energy measurement probe 100 is disposed in the beam vacuum pipe butt joint, the flange 14 is sealedly connected to the flange interface 35 of the beam vacuum pipe butt joint, and the sensing electrode 21 is located at the center of the beam vacuum pipe 3 .

[0099] In order to support the beam vacuum pipeline butt joint tube, a support plate 36 is respectively arranged on both sides of the beam vacuum pipeline butt joint tube.

[0100] refer to Fig.15 The beam energy detector also includes a preamplifier, a phase-locked amplifier, an acquisition card, a computer and an oscilloscope.

[0101] The signal input terminal of the preamplifier is connected to the signal lead-out feed-through connector of the feed-through member 24 via a signal line;

[0102] The signal output end of the preamplifier is directly connected to the signal input end of the oscilloscope and the signal output end of the oscilloscope is connected to the computer, or the signal output end of the preamplifier is connected to the acquisition card through a phase-locked amplifier, and finally the acquisition card is connected to the computer.

[0103] The preamplifier is a 50 ohm impedance matched amplifier.

[0104] A specific implementation method for directly monitoring the beam shape: the signal lead-out feedthrough connector transmits the sensing signal to the preamplifier, and after being amplified by the preamplifier, it is directly input into the oscilloscope. The shape of the beam at the sensing electrode 21 can be directly monitored by the oscilloscope. At the same time, the computer compares and analyzes the sensing signal. The time difference of the sensing signal collected by the oscilloscope and the installation distance are calculated to give the corresponding beam energy, which is displayed on the computer display screen.

[0105] A specific implementation method for real-time monitoring of beam current intensity: a signal lead-out feed-through connector transmits a sensing signal to a preamplifier, which is amplified by the preamplifier and connected to a phase-locked amplifier. The beam current after the phase-locked amplifier is collected by an acquisition card, and the beam current intensity is obtained after being processed by a computer, and is displayed on a display screen of the computer, thereby monitoring the beam current intensity in real time.

[0106] The beam energy is calculated by measuring the time difference of the beam passing and the installation distance between the two probes 100 using two beam energy measurement probes 100, specifically:

[0107] According to the distance between the two probes 100 and the time difference between their sensing signals, the particle velocity v can be calculated by the following formula:

[0108]

[0109] Where L is the distance between the two probes in meters, T is the high-frequency period in seconds, N is the number of bunches between the two probes in pieces, and t is the time difference between the sensing signals of the two probes in seconds.

[0110] The relationship between the particle velocity v and the particle's relativistic factor γ is:

[0111]

[0112] In the formula, γ is the relativistic factor of the particle, c is the speed of light, c = 299792458m / s, then the total energy E0 of a single nucleon of the particle (in MeV / u) can be expressed as:

[0113] E0=γ×ε u (Formula 3)

[0114] In the formula, ε u is the single nucleon rest energy, ε u =931.49432[MeV / u].

[0115] Finally, the particle single nucleon kinetic energy E k It can be calculated according to the following formula:

[0116] E k =E0-εu (Formula 4)

[0117] In the formula, E k is the kinetic energy of a single nucleon of the particle, E0 is the total energy of a single nucleon of the particle, ε u is the single-nucleon rest energy, which is a constant.

[0118] The velocity measurement error Δv comes from the measurement error ΔL of the distance between the two probes and the oscilloscope time measurement accuracy Δt. According to the error transfer formula, the ratio of the velocity measurement error Δv to the particle velocity v can be expressed as:

[0119]

[0120] Therefore, the relative error value of kinetic energy ΔE k and the particle single nucleon kinetic energy E k The ratio is

[0121]

[0122] Example: For a proton with a single nucleon kinetic energy of 0.75 MeV / u, the high frequency is 36.14 MHz, the distance between the probes is L = 1.97 m, N = 9, t = 21.97 ns, assuming that the distance measurement accuracy is ΔL = 1 mm, and the oscilloscope time measurement accuracy is Δt = 100 ps, ​​the relative error of the kinetic energy is calculated to be 0.1%.

[0123] Although the present invention has been described in detail above by general description and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements can be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all belong to the scope of protection claimed by the present invention.

Claims

1. A beam energy measurement probe, characterized in that: include: A shielding support body (1) comprises a shielding cylinder (11), a shielding tube (12), a support tube (13) and a flange (14); the shielding cylinder (11) is connected to one end of the support tube (13) through the shielding tube (12); the flange (14) is arranged on the other end of the support tube (13); the outer walls of the shielding cylinder (11), the shielding tube (12) and the support tube (13) are electrically connected in sequence; wherein the support tube (13) and the flange (14) are connected to each other. The connected tube end of the shielding tube (12) is closed to form a blind end (130), a feed-through piece (24) is provided at the blind end (130) of the support tube (13), one end of the shielding tube (12) is provided on the blind end (130) of the support tube (13) through the feed-through piece (24), and the other end of the shielding tube (12) is provided on the shielding tube (11), thereby realizing that the shielding tube (11), the shielding tube (12) and the outer wall of the support tube (13) are electrically connected in sequence; A signal sensing and extraction device (2), comprising a sensing electrode (21) and a feedthrough (24), wherein the sensing electrode (21) and the feedthrough (24) are electrically connected; the sensing electrode (21) is arranged on the inner wall of the shielding cylinder (11); the feedthrough (24) is arranged in the shielding support body (1) and exposes a signal extraction feedthrough connector for external connection; When the particle beam passes through the annular space in the induction electrode (21) in the shielding tube (11), the induction electrode (21) generates an induction charge to form an induction signal, which is transmitted to the feed-through component (24) and finally led out by the signal lead-out feed-through connector. The shielding support body (1) can shield the influence of environmental noise on the induction signal.

2. The beam energy measurement probe according to claim 1, characterized in that: The blind end (130) of the support tube (13) and the shielding tube (11) are connected on both sides via support rods (15), and the lengths of the two support rods (15) connecting the blind end of the support tube (13) and the shielding tube (11) are adjustable to achieve fine adjustment of the position of the shielding tube (11).

3. The beam energy measurement probe according to claim 1, characterized in that: The signal sensing and extraction device (2) further comprises an electrode connector (22) and a signal extraction terminal (23). The induction electrode (21) is a circular copper ring, which is arranged on the inner wall of the shielding cylinder (11) and is isolated and insulated from the shielding cylinder (11) by a plurality of electrical insulating parts (110); The electrode connector (22) is a copper tube body with two ends open, an electrode connector through-hole is provided at the connection between the shielding tube (12) and the shielding cylinder (11), one end of the electrode connector (22) passes through the electrode connector through-hole, and the outer wall of the other end of the electrode connector (22) is fixed on the sensing electrode (21) and is electrically connected to the sensing electrode (21); The signal lead-out terminal (23) comprises a plug pin (231) and a feed-through joint (232), wherein the feed-through joint (232) is electrically connected to the feed-through (24); the plug pin (231) comprises a guide core (2311) and a strip cluster mesh cover (2312), wherein the guide core (2311) is fixedly connected to the feed-through joint (232), the plug pin (231) is inserted into the electrode joint (22), and the middle part of the strip cluster mesh cover (2312) contacts the inner wall of the electrode joint (22), and the two are plugged and matched with each other.

4. The beam energy measurement probe according to claim 3, characterized in that: The strip cluster mesh cover (2312) includes a plurality of Hastelloy strips, both ends of which are fixed to the feed-through butt joint (232), and the Hastelloy strips are clustered around the guide core (2311) to form the thick strip cluster mesh cover (2312) in the middle.

5. The beam energy measurement probe according to claim 4, characterized in that: The feedthrough butt joint (232) is a cylinder, and the guide core (2311) is fixed to the center of the bottom surface of the feedthrough butt joint (232) and is integrally formed to ensure that the guide core (2311) is still located in the center of the bar cluster mesh cover (2312) after the Hastelloy bar of the bar cluster mesh cover (2312) is squeezed; The Hastelloy bars of the bar cluster mesh cover (2312) elastically bulge out in all directions when not under pressure, and the outer diameter of the middle part of the bar cluster mesh cover (2312) is larger than the inner diameter of the inner wall of the electrode joint (22). When the pin (231) is inserted into the electrode joint (22), the Hastelloy bars of the bar cluster mesh cover (2312) are compressed and contracted, and touch the inner wall of the electrode joint (22) inside the electrode joint (22) and are forced to close.

6. The beam energy measurement probe according to claim 3, characterized in that: The feedthrough (24) comprises a conductive intermediate body (241), an electrical insulating layer (242) and a shielding sleeve (243). The blind end (130) of the support tube (13) is provided with a feed-through hole, the shielding sleeve (243) is fixed on the feed-through hole, and two ends of the shielding sleeve (243) are respectively electrically connected to the blind end (130) of the support tube (13) and the shielding tube (12); The conductive intermediate (241) passes through the interior of the shielding sleeve (243) and exposes both ends; The electrical insulation layer (242) is made of ceramic material, and the electrical insulation layer (242) is disposed in the annular space between the conductive intermediate body (241) and the shielding sleeve (243), separating the conductive intermediate body (241) from the shielding sleeve (243); The outer ends of the conductive intermediate body (241) and the shielding sleeve (243) extend outward to form a signal lead-out feed-through connector, which is used as an external interface; The inner end of the conductive intermediate body (241) is fixedly connected to the feed-through joint (232) of the signal lead-out terminal (23).

7. The beam energy measurement probe according to claim 6, characterized in that: The shielding sleeve (243) is nested in the shielding tube (12), and a conductive net (251) and a clamp (252) are provided at the connection between the shielding sleeve (243) and the shielding tube (12). The conductive mesh (251) comprises a plurality of Hastelloy alloy bars, which form a circle around the outer wall of the shielding tube (12), and one end of each Hastelloy alloy bar extends into the tube mouth of the shielding tube (12) to contact the outer wall of the shielding sleeve (243) of the feed-through (24) and is clamped by the tube mouth of the shielding tube (12), and one end of each Hastelloy alloy bar is distributed on the outer wall of the shielding tube (12) and is clamped by the clamp (252).

8. A beam energy detector, characterized in that: The invention comprises a plurality of beam energy measurement probes (100) as claimed in any one of claims 1 to 7, which are used for being installed on a beam vacuum pipe (3) between a cyclotron (4) and a synchronization ring (5) of a medical heavy ion accelerator. The beam energy detector comprises a beam vacuum pipeline butt joint pipe, on which a beam vacuum pipeline inlet (31), a beam vacuum pipeline outlet (32), a molecular pump interface (33), an ion pump interface (34) and a flange interface (35) are arranged. The beam vacuum pipeline inlet (31) and the beam vacuum pipeline outlet (32) are arranged opposite to each other and are used to be installed on the beam vacuum pipeline (3) and docked therewith; The molecular pump interface (33) and the ion pump interface (34) are used to dock the molecular pump and the ion pump respectively, so as to maintain the vacuum environment in the beam vacuum pipeline docking tube; The beam energy measurement probe (100) is arranged in the beam vacuum pipe butt joint tube, the flange (14) is sealedly connected to the flange interface (35) of the beam vacuum pipe butt joint tube, and the sensing electrode (21) is located at the center of the beam vacuum pipe (3); The beam energy detector also includes a preamplifier, a phase-locked amplifier, an acquisition card, a computer and an oscilloscope. The signal input end of the preamplifier is connected to the signal lead-out feedthrough connector of the feedthrough component (24) via a signal line; The signal output end of the preamplifier is directly connected to the signal input end of the oscilloscope and the signal output end of the oscilloscope is connected to the computer, or the signal output end of the preamplifier is connected to the acquisition card through a phase-locked amplifier, and finally the acquisition card is connected to the computer.

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